Filter



FIG. 1 is a perspective view of a filter showing my new design;

FIG. 2. is a front elevational view thereof;

FIG. 3. is a rear elevational view thereof;

FIG. 4. is a left side view thereof;

FIG. 5. is a right side view thereof;

FIG. 6 is a top plan view thereof; and,

FIG. 7 is a bottom plan view thereof. 

The ornamental design for a filter, as shown and described. 